On 28 February 2006 18:42, Jacques Carette wrote:
What *problem* are you actually trying to solve here?
The problem that 'realToFrac (0/0 :: Float) :: Double' doesn't give you NaN, and similarly for the other special float values.
If it is "conversion between floating point types", then there are other solutions that do not need to ``pollute'' exact arithmetic. I did not see any tickets on this -- did I miss it/them? This is one issue where I should go and contribute, as I've been part of a team that has done just this to a programming language before, so at least I can claim to know the pitfalls to avoid!
Please go ahead and create a ticket. I don't claim to know a great deal about floating point, but Cale Gibbard's suggestion (use encodeFloat.decodeFloat) looks reasonable to me. I have an old item on my GHC ToDo list that says "make encodeFloat.decodeFloat work for NaN" :-) Cheers, Simon